Southern California -- this just in

Intense Southland heat wave brings record temperatures, brush fires

The heat wave that has brought record-setting conditions to Southern California will continue through the weekend, causing firefighters to be on heightened alert.

On Friday, Palmdale and Lancaster set new records for the day, with a high of 109 degrees.

Temperatures on Saturday should be slightly lower but will still be well above 100 degrees in inland areas, according to the National Weather Service. Next week should bring a bit more relief, forecasters said.

A fire raging in northern San Diego County had burned 1,650 acres by Friday evening. Two smaller fires in San Bernardino and Ventura counties charred dozens of acres before being contained.

The wide-ranging fire in San Diego County was sparked by a lightning strike Thursday. Early on, several hundred firefighters struggled to contain it. They were helped Friday afternoon by thundershowers, and the blaze was 30% contained by Friday evening, according to the California Department of Forestry and Fire Protection.

Several communities — including Woodland Hills and Sandberg, which is near Interstate 5 north of Santa Clarita — had record-breaking heat, and an excessive-heat warning was in effect for most of the day. Temperatures in Lancaster and Palmdale reached 109 degrees, which also set records for the date.

Bonnie Bartling, a weather specialist with the National Weather Service, said the region was already dry and highly susceptible to fires before the current heat wave began.

"We haven't had a lot of rain," she said. "We're just drying out. So any little spark — people working on equipment or who aren't paying attention and throw a match — it's just more ignitable right now."

Case in point: A brush fire on the grounds of the California Institution for Men in Chino was probably started by a prison vehicle.

The fire had burned 25 to 30 acres Friday afternoon but was mostly contained by evening. A spokesman for the prison said a preliminary investigation suggested that the fire was caused when a prison vehicle malfunctioned near dry vegetation.

In Ventura County, a brush fire believed to have been caused by vehicle exhaust burned about 27 acres along the Conejo Grade off the 101 Freeway. The blaze was fully contained by Friday evening.

The high temperatures prompted the state's power grid operator to issue a "flex-alert," urging residents to reduce their energy use during the afternoon. The alert was in effect Thursday and Friday but was lifted for the weekend.